Aquarium filter



FIG. 1 is a front respective view of an aquarium filter showing my newdesign;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a bottom view thereof;

FIG. 6 is a side view thereof; and,

FIG. 7 is the opposite view of FIG. 6 thereof.

The ornamental design for an aquarium filter, as shown and described.